From a1df417e74aa6dae7352dc8cbb0ad471af5b7c69 Mon Sep 17 00:00:00 2001 From: "Michael J. Chudobiak" Date: Mon, 25 Apr 2016 10:00:44 -0400 Subject: initial Olimex linux tree from Daniel, originally Feb 3, 2016 --- linux/arch/arm64/include/asm/stackprotector.h | 38 +++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 linux/arch/arm64/include/asm/stackprotector.h (limited to 'linux/arch/arm64/include/asm/stackprotector.h') diff --git a/linux/arch/arm64/include/asm/stackprotector.h b/linux/arch/arm64/include/asm/stackprotector.h new file mode 100644 index 00000000..fe5e287d --- /dev/null +++ b/linux/arch/arm64/include/asm/stackprotector.h @@ -0,0 +1,38 @@ +/* + * GCC stack protector support. + * + * Stack protector works by putting predefined pattern at the start of + * the stack frame and verifying that it hasn't been overwritten when + * returning from the function. The pattern is called stack canary + * and gcc expects it to be defined by a global variable called + * "__stack_chk_guard" on ARM. This unfortunately means that on SMP + * we cannot have a different canary value per task. + */ + +#ifndef __ASM_STACKPROTECTOR_H +#define __ASM_STACKPROTECTOR_H + +#include +#include + +extern unsigned long __stack_chk_guard; + +/* + * Initialize the stackprotector canary value. + * + * NOTE: this must only be called from functions that never return, + * and it must always be inlined. + */ +static __always_inline void boot_init_stack_canary(void) +{ + unsigned long canary; + + /* Try to get a semi random initial value. */ + get_random_bytes(&canary, sizeof(canary)); + canary ^= LINUX_VERSION_CODE; + + current->stack_canary = canary; + __stack_chk_guard = current->stack_canary; +} + +#endif /* _ASM_STACKPROTECTOR_H */ -- cgit